摘要:
水源水中存在数以万计的污染物,需要根据不同水源污染特征筛查相应的特征污染物,并确定其对人体产生的健康风险。针对官厅水库及其出入库河流的表层水样,采用气相色谱质谱方法,对77种有机污染物进行了目标筛查和定量分析;采用非目标筛查的方法,对1 655种有机污染物进行了定性筛查。定量分析检出43种挥发性有机物(VOCs),浓度为nd~8.17 μg ·L-1;8种羰基化合物,浓度为nd~5.04 μg·L-1;7种嗅味物质,浓度为nd~1 421.58 ng·L-1。在检出的58种污染物中,有国家生活饮用水卫生标准(GB5749-2006)的共有23种,有国家地表水环境质量标准(GB3838-2002)的22种,浓度均未超过相关标准。对所检出的污染物进行了危害识别,发现5种嗅味物质浓度均超过了其嗅阈值。对其中有基础毒性数据的17种污染物进行了致癌风险评价,对37种污染物进行了非致癌风险评价。研究表明,17种污染物致癌风险处于10-6~10-5水平,而37种污染物的非致癌风险处于10-2水平,均低于国际认同的风险控制阈值。定性筛查出80种具有潜在健康风险的有机污染物,作为进一步深入研究的目标污染物。据此,2012年调查中官厅水库水中的有机微污染对人体健康的风险总体上处于较低水平。其中,苯系物在官厅水库中普遍存在,六氯丁二烯和巴豆醛是主要的风险特征污染物,2-异丙基-3-甲氧基吡嗪(IPMP)、2-异丁基-3-甲氧基吡嗪(IBMP)和2,4,6-三氯茴香醚(TCA)是主要的致嗅特征污染物。
Abstract:
In the risk management, it is quite necessary to screen for a limited number of site-specific priority contaminants of potential health risk. In this paper, water samples were collected from Guanting Reservoir of Beijing, China and organic contaminants were analyzed both quantitatively and qualitatively by gas chromatography-mass spectrometry. From quantitative results, it showed that 43 volatile organic compounds (VOCs), 8 carbonyl compounds, and 7 taste and odor compounds could be identified from 77 targets. The concentrations of VOCs, carbonyl compounds, and taste and odor compounds were in the range of nd~8.17 μg·L-1, nd~5.04 μg·L-1, and nd~1 421.58 ng·L-1, respectively. Among the 58 detected contaminants, 23 were regulated by the standards for drinking water quality (GB5749-2006) and 22 by the environmental quality standards for surface water (GB3838-2002). None of these regulated contaminants exceeded the standards. In 58 detected contaminants, 5 taste and odor compounds with odor thresholds were evaluated for taste and odor concerns. 17 contaminants with the carcinogenic data were evaluated for carcinogenic risks while 37 with toxicological data were evaluated for non-carcinogenic risks. Results showed that 5 taste and odor compounds all exceeded their odor thresholds. The total carcinogenic risks were at levels of 10-6~10-5, and the total noncarcinogenic risks were at the level of 10-2, both of which were in the acceptable ranges of the US EPA. In qualitative analysis, a total of 80 contaminants were screened from 1 093 compounds as potential health risk contaminants for further verification. In conclusion, the health risk associated with organic micro-contaminants in the water of Guanting reservoir was at a low level if served as the drinking water source of Beijing. Benzene-containing compounds should be the major concern. Hexachlorobutadiene and crotonaldehyde were the risky priority contaminants with relatively higher risks while 2-isopropyl-3-methoxypyrazine (IPMP), 2-isobutyl-3-methoxypyrazine (IBMP) and 2,4,6-trichloroanisole (TCA) were the odor-causing priority contaminants.
点击查看大图
下载:
